bug#32338: 26.1; term.el broken on macOS

[Noam Postavsky <npostavs@gmail.com>]

Constantine Vetoshev <vetoshev@gmail.com> writes:

> M-x term nor M-x ansi-term both cause Emacs to lock up on macOS
> 10.13.4. Steps to reproduce with -Q:
>
> 1. M-x ansi-term
> 2. Type in /bin/bash, hit Enter
>
> You'll notice that a prompt does not appear in the resulting window
> (*ansi-term* buffer). Hit Enter. Emacs will display "Writing to process:
> Input/output error, *ansi-term*" in the minibuffer. If you started Emacs
> from the terminal, it will display "Fatal error 4: Illegal
> instruction".

Do you mean Emacs itself is hitting this error and crashing, or
/bin/bash running inside *ansi-term* does?  Can you run under a debugger
and get a backtrace?

> After this, Emacs becomes unstable and will eventually
> stop responding to input. All this worked fine in 25.3 and earlier
> (i.e., a shell prompt appears and can be readily used).

Does it currently work fine on 25.3 (i.e., is it possible an OS update
caused this to stop working on earlier Emacs versions as well)?  If you
load term.el from 25.3 into 26.1 does it work then?

> In GNU Emacs 26.1 (build 1, x86_64-apple-darwin17.5.0, NS
> appkit-1561.40 Version 10.13.4 (Build 17E202))
>  of 2018-05-29 built on athena
> Windowing system distributor 'Apple', version 10.3.1561